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  • Anura3D Training Course

    Submitted by Alexander Rohe on Fri, 09/06/2017 - 13:48

    Modelling large deformation and soil–water–structure interaction using the material point method

    Friday, 29 September 2017
    Hamburg University of Technology (TUHH), Germany

    Large deformation and soil–water–structure interaction exists in many environmental and civil engineering problems, such as landslides and slope instabilities, installation of piles in saturated soils, settlement due to consolidation processes, fluidisation and sedimentation processes in sub-merged slopes, internal erosion in dykes, and scouring around offshore structures. Modelling these processes is challenging due to hydro-mechanical coupling, large deformation, and contact problems.

    The material point method (MPM) is a numerical approach capable of modelling large deformations and recently, within the framework of the MPM Research Community, it has been extended to cope with soil–water–structure interaction.

    The Anura3D v2017.1 software uses a dynamic explicit MPM formulation based on a single set of material points. This is capable of simulating 1- and 2-phase materials and free surface water. A fully coupled hydro-mechanical approach is implemented to model the interaction between soil and water phases in saturated porous media, which is understood as a continuum mixture of solid skeleton and pore fluid. Additionally, contact problems can also be solved since a contact algorithm is available. Finally, a library of material constitutive laws is included as well as a umat style interface for external user defined soil models subroutines.

  • MPM Training Course

    Submitted by Alexander Rohe on Mon, 14/11/2016 - 15:54

    Modelling large deformation and soil–water–structure interaction using the material point method

    12–13 January 2017
    Deltares, Delft, The Netherlands

    Large deformation and soil–water–structure interaction exists in many environmental and civil engineering problems, such as landslides and slope instabilities, installation of piles in saturated soils, settlement due to consolidation processes, fluidisation and sedimentation processes in submerged slopes, internal erosion in dykes, and scouring around offshore structures. Modelling these processes is challenging due to hydro-mechanical coupling, large deformation, and contact problems.
    The material point method (MPM) is a point-based numerical approach capable of modelling large deformations and recently, within the framework of the MPM Research Community, it has been extended to cope with complicated soil–water–structure interactions.

  • First International Conference on the Material Point Method for Modelling Large Deformation and Soil–Water–Structure Interaction (MPM2017)

    Submitted by Alexander Rohe on Mon, 03/10/2016 - 17:01

    10–13 January 2017
    Deltares Delft, The Netherlands

    We are delighted to invite you to join us at the First International Conference on the Material Point Method for “Modelling Large Deformation and Soil–Water–Structure Interaction” organised by the Anura3D MPM Research Community in January 2017 in Delft. This is the first conference following a series of international workshops and symposia previously held in Padova (2016), Barcelona (2015), Cambridge (2014) and Delft (2013).

    The aim of the conference is to provide an international forum for presenting and discussing the latest developments in both the fundamental basis and the applicability of state-of-the-art computational methods that can be effectively used for solving a variety of large deformation problems in geotechnical and hydraulic engineering. Special focus is on the numerical modelling of interaction between soils, water and structures where the interface and transition between solid and fluid behaviour plays an essential role.

    For more information and the latest news regarding the conference programme and registration, please regularly visit our website at www.mpm2017.eu.

    We are looking forward to welcoming you in Delft in January 2017!
    The MPM 2017 Organising Committee

  • Thesis Defence: Roel Tielen

    Submitted by Alexander Rohe on Mon, 27/06/2016 - 14:08

    High-order material point method

    R.P.W.M. Tielen

    Date and Time
    Wednesday, 6 July 2016, 15:30 h
    Location
    Delft University of Technology, Faculty EEMCS (building 36), Lecture hall "Chip"

    Abstract
    The material point method (MPM) is a meshfree mixed Lagrangian-Eulerian method which utilizes moving Lagrangian material points that store physical properties of a deforming continuum and a fixed Eulerian finite element mesh to solve the equations of motion for individual time steps. MPM proved to be successful in simulating mechanical problems which involve large deformations of history-dependent materials. The solution on the background grid is found in MPM by a variational formulation. The integrals resulting from this formulation are numerically approximated by using the material points as integration points. However, the quality of this numerical quadrature rule decreases when the material points become unevenly distributed inside the mesh.

    It is common practice in MPM to adopt piecewise linear basis functions for approximating the solution of the variational form. A problem arises from the discontinuity of the gradients of these basis functions at element boundaries leading to unphysical oscillations of computed stresses when material points cross element boundaries. Such grid crossing errors significantly affect the quality of the numerical solution and may lead to a lack of spatial convergence.

  • First MPM-DREDGE Training Course

    Submitted by Alexander Rohe on Thu, 12/05/2016 - 22:01

    The course material of the First MPM-DREDGE Training Course held on 3 May 2016 at the University of Cambridge is now available on this website.

  • REMINDER: Abstract submission deadline -- 4 April 2016

    Submitted by Alexander Rohe on Thu, 31/03/2016 - 10:53

    First International Conference on the Material Point Method for
    Modelling Large Deformation and Soil–Water–Structure Interaction

    10–13 January 2017, Delft, The Netherlands

    We are delighted to invite you to join us at the First International Conference on the Material Point Method for “Modelling Large Deformation and Soil–Water–Structure Interaction” organised by the MPM Research Community in January 2017 in Delft. This is the first conference following a series of international workshops and symposia previously held in Barcelona (2015), Cambridge (2014) and Delft (2013) in the context of the FP7 Marie-Curie project MPM-DREDGE.

    The aim of the conference is to provide an international forum for presenting and discussing the latest developments in both the fundamental basis and the applicability of state-of-the-art computational methods that can be effectively used for solving a variety of large deformation problems in geotechnical and hydraulic engineering. Special focus is on the numerical modelling of interaction between soils, water and structures where the interface and transition between solid and fluid behaviour plays an essential role.

    Papers on any aspect of these subjects are most welcome. Active discussion on key topics will be facilitated through invited keynote lectures. In addition, the partners of the MPM-DREDGE project will present the highlights of their research programme, achieved through intense collaboration between industry and academia. The results include validated computational tools based on the material point method to improve the understanding of installation of geocontainers, liquefaction of submarine slopes, landslides and erosion around offshore and near-shore structures.

  • Thesis defence: Shuhong Tan

    Submitted by Alexander Rohe on Mon, 21/03/2016 - 12:25

    Dynamic finite element investigation of wave attack on sea dikes: A coupled approach using plate and volume elements

    Shuhong Tan

    Date and Time
    Wednesday, 30 March 2016, 15:00 h
    Location
    Delft University of Technology, Aula Congres Centre (Mekelweg 5), Senate Room

    Abstract
    Approximately 400 kilometres of Dutch sea dikes are protected by bituminous concrete revetments to prevent damage from erosion and repeated wave attacks during storms. The numerical analysis of sea dikes subjected to cyclic wave loading needs to consider the behaviour of the bituminous concrete revetment, and the behaviour of the subsoil including the generation and dissipation of the excess pore pressures, as well as the interaction between the revetment and subsoil. This thesis develops and evaluates numerical methods for investigating this problem, using the dynamic Finite Element Method with the coupling of plate and volume elements.

    In dynamic finite element analysis, the arbitrary selected boundary generates wave reflections which normally causes oscillation problems. Absorbing boundary conditions are therefore adopted to minimise the wave reflection at the artificial boundaries. The effects of the absorbing boundary conditions are investigated in detail for both solid and water phases, and appropriate sets of parameters are recommended.

  • MPM-DREDGE Training Course

    Submitted by Alexander Rohe on Thu, 25/02/2016 - 16:26

    Modelling large deformation and soil–water interaction using the Material Point Method

    Date and Time
    Tuesday, 3 May 2016, 8:30 h - 17:00 h
    Location
    University of Cambridge, Engineering Department, Trumpington Street, Cambridge CB2 1PZ
    Registration Form
    Registration is closed.
    Speakers
    Prof. Kenichi Soga, Dr. Dongfang Liang, Dr. Mario Martinelli, Dr. Francesca Ceccato, Dr. Alexander Rohe, Dr. Alba Yerro
    Registration Fee
    75 £ (includes: coffee, lunch, and tutorials)
    Registration deadline
    29 April 2016
    Number of participants
    Limited to 20

    Soil–water interaction

    Soil–water interaction exists in many environmental and civil engineering problems, such as landslides induced by rainfall, fluidisation and sedimentation processes in submerged slopes, internal erosion in dykes, scouring around offshore structures, settlement due to consolidation processes and installation of piles in saturated soils. Modelling these processes is challenging due to soil–water coupling and large deformation.
    MPM is a point-based numerical method capable of modelling large deformations and recently, within the framework of the MPM Research Community, it has been extended to cope with complicated soil-fluid interactions.
    This training course focuses on presenting those MPM formulations cable of simulating the interaction between soil and water phases. Two different approaches will be addressed. In the first one, a single set of material points describes the behaviour of saturated porous media understood as a mixture of solid skeleton and pore fluid. The second approach describes the movement of each constituent (i.e. solid and fluid) individually by means of two sets of material points, thereby enabling the simulation of free water and the in and outflow, as well as fluidisation and sedimentation processes.

  • Thesis Defence: Jakob Maljaars

    Submitted by Alexander Rohe on Wed, 06/01/2016 - 22:08

    A hybrid particle-mesh method for simulating free surface flows

    J.M. Maljaars

    Date and Time
    Friday, 29 January 2016, 15:00 h
    Location
    Delft University of Technology, Faculty EEMCS (building 36), Lecture hall "Chip"

    Abstract
    Hybrid particle-mesh methods attempt to combine the advantages of Eulerian and Lagrangian methods: Lagrangian particles are used for the advection, whereas a Eulerian background grid is used for computing the particle interactions. Such a hybrid approach is expected to have several benefits when simulating flows involving free surfaces or material interfaces: the particles can be efficiently used to track the free surface, while the background grid can be used to solve the governing Navier-Stokes equations and impose the incompressibility constraint in a convenient manner. The prospects of these hybrid particle-mesh methods for simulating incompressible fluid flows involving a free surface are assessed in this thesis. More specifically, the feasibility of setting-up a numerical wave flume using hybrid particle-mesh methods is investigated.

  • MPM 2017 Conference

    Submitted by Alexander Rohe on Mon, 14/09/2015 - 15:05

    First International Conference on the Material Point Method for
    Modelling Large Deformation and Soil–Water–Structure Interaction

    10–13 January 2017, Delft, The Netherlands

    We are delighted to invite you to join us at the First International Conference on the Material Point Method for “Modelling Large Deformation and Soil–Water–Structure Interaction” organised by the MPM Research Community in January 2017 in Delft. This is the first conference following a series of international workshops and symposia previously held in Barcelona (2015), Cambridge (2014) and Delft (2013) in the context of the FP7 Marie-Curie project MPM-DREDGE.

    The aim of the conference is to provide an international forum for presenting and discussing the latest developments in both the fundamental basis and the applicability of state-of-the-art computational methods that can be effectively used for solving a variety of large deformation problems in geotechnical and hydraulic engineering. Special focus is on the numerical modelling of interaction between soils, water and structures where the interface and transition between solid and fluid behaviour plays an essential role.

    Papers on any aspect of these subjects are most welcome. Active discussion on key topics will be facilitated through invited keynote lectures. In addition, the partners of the MPM-DREDGE project will present the highlights of their research programme, achieved through intense collaboration between industry and academia. The results include validated computational tools based on the material point method to improve the understanding of installation of geocontainers, liquefaction of submarine slopes, landslides and erosion around offshore and near-shore structures.

  • First prize at EMI 2015

    Submitted by Alexander Rohe on Mon, 22/06/2015 - 16:17

    James Fern won the first prize at the 'Dr Masao Satake Memorial Symposium on Granular Mechanics' at ASCE EMI 2015, Stanford University, California, for the work on the granular column collapse.

    On behalf of the MPM Research Community we would like to congratulate James for this achievement.

    James (second from the right) receiving his award at EMI 2015.

  • Géotechnique: "The material point method for unsaturated soils"

    Submitted by Alexander Rohe on Wed, 25/03/2015 - 10:33

    Alba Yerro, Eduardo Alonso, Núria Pinyol
    DOI: 10.1680/geot.14.P.163

    Abstract
    The paper describes a three-phase single-point material point method formulation of coupled flow (water and air) for hydro-mechanical analysis of geotechnical problems involving unsaturated soils. The governing balance and dynamic momentum equations are discretised and adapted to material point method characteristics: an Eulerian computational mesh and a Lagrangian analysis of material points. General mathematical expressions for the terms of the set of governing equations are given. A suction-dependent elastoplastic Mohr–Coulomb model, expressed in terms of net stress and suction variables is implemented. The instability of a slope subjected to rain infiltration, inspired from a real case, is solved and discussed. The model shows the development of the initial failure surface in a region of deviatoric strain localisation, the evolution of stress and suction states in some characteristic locations, the progressive large strain deformation of the slope and the dynamics of the motion characterised by the history of displacement, velocity and acceleration of the unstable mass.

    Keywords
    strain localisation, slopes, plasticity, dynamics, partial saturation, numerical modelling

    View full publication

  • TUHH forscht an Software zur Simulation großer Bodenverformungen

    Submitted by Alexander Rohe on Thu, 23/10/2014 - 14:18

    Die Technische Universität Hamburg (TUHH) beteiligt sich an einer europäischen Forschungsgemeinschaft, zur Verbesserung einer Software, die große Bodenverformungen und -bewegungen simulieren kann. Initiiert wurde die Kooperation von dem unabhängigen niederländischen Forschungsinstitut Deltares, das Lösungen zum Schutz von Flussmündungen, Küsten und Fließgewässern entwickelt. Neben der TUHH sind die University of Cambridge, Großbritannien, und die Universidad de Barcelona, Spanien, mit sehr renommierten Wissenschaftlern an dem Vorhaben beteiligt.

    Professor Jürgen Grabe, Leiter des Instituts für Geotechnik und Baubetrieb, fuhr nach Delft, um mit den beteiligten Wissenschaftlern die zukünftige Zusammenarbeit zu unterzeichnen. Ziel der Zusammenarbeit ist es, eine numerische Berechnungsmethode, die sogenannte „Material Point Method“ (MPM), so weiterzuentwickeln, dass damit große dynamische Deformationen vom Boden (Bodenpartikel, Porenwasser, Porenluft) simuliert werden können. Es geht dabei beispielsweise um die Simulation der schlagenden Einbringung von Gründungspfählen von Offshore Windenergieanlagen in den Meeresgrund, von großen Erdrutschen nach starken Niederschlägen oder das Versagen eines Deiches infolge anhaltenden Hochwassers und Wellenschlags. Die Simulationsergebnisse werden mit Ergebnissen aus Labor- und Feldversuchen verglichen und auf diese Weise validiert.

    View the original news item

  • Computers and Geotechnics: "Coupling of soil deformation and pore fluid flow using material point method"

    Submitted by Alexander Rohe on Mon, 20/10/2014 - 09:34

    Samila Bandara, Kenichi Soga
    DOI: 10.1016/j.compgeo.2014.09.009

    Abstract
    This paper presents the formulation and implementation of a numerical procedure based on material point method (MPM) to solve fully coupled dynamic problems that undergo large deformations in saturated soils. The key aspect of this formulation is that it considers two sets of Lagrangian material points to represent soil skeleton and pore water layers. The accuracy of the method is tested by comparing the results to some analytical solutions of consolidation theory. The developed method has been applied to model progressive failure of river levees to illustrate the practical applications. The numerical results show the robustness of the proposed method with regard to large deformations that undergo rapid failure mechanisms.

    Keywords
    Material point method, Saturated soil, Large deformations, Dynamic coupled analysis, Meshfree methods, River levees

    View full publication

  • DredgingToday.com

    Submitted by Alexander Rohe on Wed, 08/10/2014 - 12:23

    Deltares to Further Develop MPM

    Deltares has begun a collaboration with the universities of Cambridge, Barcelona and Hamburg to establish a research community for the numerical modeling of soil interacting with water.

    Read the full article at DredgingToday.com

  • European collaboration on development of numerical design tool

    Submitted by Alexander Rohe on Tue, 07/10/2014 - 18:18

    Deltares started a collaboration with the universities of Cambridge, Barcelona and Hamburg to establish a research community for the numerical modelling of soil interacting with water. The aim is to further develop a dynamic calculation method, the Material Point Method (MPM), making it suitable to apply for contractors, designers and engineering companies. MPM is used to analyse large deformations and large movements of soil and water, for example to simulate the installation of a piled foundation, the failure of a dike or the sliding of an underwater slope. Further development of MPM will enable us to improve our understanding of the consequences of large soil deformations. The software will be validated using laboratory and field experiments.

  • Terugblik Nederlandse deelname aan het Zevende Kaderprogramma voor Onderzoek en Technologische Ontwikkeling (KP7)

    Submitted by Alexander Rohe on Thu, 19/06/2014 - 16:17

    Nederland moet het hebben van kennis en innovatie. Ons land heeft geen overschot aan grondstoffen en de aardgasbaten zullen op termijn achteruitlopen. Ook kent ons land geen massaproductie op basis van lage lonen. De belangrijkste motor voor onze economie is dus kennis, kennis en nog eens kennis. Een mooi voorbeeld van hoogwaardige, door kennis gedreven, productie is ASML, waar geen chips worden geproduceerd maar geavanceerde apparaten waar chips mee worden gemaakt. Gebaseerd op state-of-the-art kennis op dit gebied, ontwikkeld door de Nederlandse fundamentele en toegepaste kennisinstituten. Een ander voorbeeld is het onderzoek in de kwantummechanica, dat mogelijk zal leiden tot de ontwikkeling van de kwantumcomputer die de huidige computers in snelheid en rekenkracht ontelbare malen zal overtreffen. Om tot nieuwe kennis en innovatie te kunnen komen moeten onderzoekers en bedrijven op de beste plek, met de beste faciliteiten en met de beste partners hun werk kunnen doen. Europa maakt die grensoverschrijdende samenwerking mogelijk en de EU stelt daar ook financiering voor beschikbaar. In 2014 is het nieuwe EU-programma hiervoor, Horizon 2020, van start gegaan. Het Zevende Kaderprogramma (KP7, 2007-2013) is daarmee afgerond. Daarvan kan nu de balans worden opgemaakt.

  • MaritiemNederland.com

    Submitted by Alexander Rohe on Thu, 15/05/2014 - 17:51

    Deltares voorspelt interactie tussen ondergrond en water

    Door baggerwerkzaamheden treden veranderingen op in de ondergrond. Het voorspellen en in kaart brengen van die veranderingen kan alleen met dure en tijdrovende praktijkproeven. Daarom ontwikkelt Deltares hiervoor een computerprogramma. ...

    Read the full article at MaritiemNederland.com

  • Ontwikkeling nieuwe analysetool versterkt positie Europese baggerindustrie

    Submitted by Alexander Rohe on Mon, 26/08/2013 - 12:23

    Marie Curie Industry Academia Partnership & Pathways (IAPP) stimuleert de uitwisseling van jonge en ervaren onderzoekers tussen organisaties uit de niet-commerciële (universiteiten) en commerciële sector (bedrijfsleven). Het Nederlandse kennisinstituut Deltares gaat in het IAPP-project MPM-DREDGE samenwerken met Cambridge University aan een geavanceerde tool voor het analyseren van baggeroperaties.

    Innovatieve simulatie
    Alexander Rohe en Joost Breedeveld (beiden adviseur/onderzoeker Deltares) onderzoeken drie hoofdonderwerpen voor de baggerindustrie: installatie van geocontainers, zettingsvloeiing en erosie. Breedeveld: “Voor het analyseren van problemen waarin zeer grote grondvervormingen in combinatie met water een rol spelen is nog geen geavanceerde tool beschikbaar. Cambridge en Deltares werken daarom samen aan de ontwikkeling en validatie hiervan.” De analysetool is een waardevolle aanvulling op complexe praktijkproeven voor de baggerindustrie, die vaak als duur worden ervaren. Rohe: “Vooral het modelleren van erosie is zeer innovatief en een grensverleggende ontwikkeling.”

    Best of both worlds
    Het IAPP programma ondersteunt het vormen van langdurige, strategische samenwerkingsverbanden tussen universiteiten en de commerciële sector. Breedeveld: “We vullen elkaar perfect aan. Cambridge heeft een van de beste onderzoeksgroepen ter wereld wat betreft grondmechanica. Deltares vertaalt de fundamentele kennis van Cambridge in een bruikbare tool voor de baggerindustrie. Rohe: “Wij leren van hun fundamentele onderzoek, doen modelproeven en hebben contacten met de baggerindustrie.” Breedeveld: “Ook na deze vier jaar willen we met elkaar blijven samenwerken.”